Screw-propeller.



PATENTED MAY 28, 1907. W. PREIDEL. V

SCREW PROPELLER.

APPLICATION FILED DEO.5.1905.

2 SHEETS-SHEET 1'.

W. PREIDEL.

SCREW PROPBLLBR. APPLICATION FILED 13110.5.1905.

2 SHEETS-SHEET 2. 1 2 5 g Y PATBNTED MAY 28, 1907.

'made according to my invention.

UNITED STATES PATENT OFFIOE.

SCHEW-PROPELLER.

Specification of Letters Patent.

Patented May 28, 1907.

Application filed December 5, 1905. Serial No. 290,393.

To all whom it may concern.-

Be it known that I, WENZEL PREIDEL, a subject of the Emperor of Austria, residing at 4 Magdalen Parade, Garratt Lane, Earlsfield, London, England, have invented new and useful Im rovements in Screw-Propellers of which the fbllowing is a specification.

This invention relates to im rovements in screw propellers, the object eing to so construct the same that lateral slip between the propeller and the medium in which it rotates is obviated.

According to the invention I provide a cylindrical, conical or similar ring around the outside of the pro eller, the tips of the blades being connecte to the inner surface of the said ring, the axis of which is coinci dent with that of the propeller boss; ring may be continuous, or it may be broken at one ormore points, in which case it isin the form of a number of segments attached to the tips of the propeller blades. The ring, is open at both sides and those portions between the adj acentblades are recessed or cut away at one side, the recesses extending to say about the center of the boss of the propeller.

To enable the invention to be fully understood I will describe it by reference to the accompanying drawings, in which Figure 1 is a side elevation of a ropeller *ig. 2 is a section on the line 2-2, Fig. 1. Fig. 3 is a plan view thereof. Fig. 4 is a development of a art of the ring. Fig. 5 is a view similar to Fig. 3 illustrating a modification, and Fig. 6 is a lan view thereof.

Re errin first to the arrangement illustrated in Figs. 1 to 4 a is the boss of the propeller and b, b, b the blades thereof. 0 is the ring which is provided around the outside of the propeller and the axis of which is coincident with that of the boss a. In the arrangement illustrated in the drawing the ring 0 is continuous and the tips of the blades 1), b are connected to its inner surface as clearly shown, the inner or inside end of the said ring being cut away so as to form the recesses d, d between the propeller blades b, b;

The

these recesses extend, as above mentioned, to about the center of the boss (I of the propeller.

By constructing a propeller as above described, the water (or air) in which the propeller is revolving, is forced through the ring more or less like a solid column in a direction opposite to that in which the vessel to which the propeller is attached is to move, thus obviati'ng lateral slip from the propeller blades.

In the arrangement illustrated in Figs. 5 and 6 I have shown the ring made'in two parts, e and f, the portion 6 being composed of segments forming the recesses d, d and attached to the tips of the propeller blades b and the portion f being fixed so as not to rotate with the propeller, that is to say, being secured in place by means of the stays g to the rear of the vessel. With this construction it will be clear that a certain amount of friction between the rotating ring and the water is avoided.

In some cases, in lieu of a recessed continuous ring, I may make use of a discontinuous ring, that is to say, of a number of segments which are attached to the tips of the propeller blades. I prefer, however, to use a continuous ring as above described.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In a screw propeller, the combination with blades of a ring encircling the ends of said blades and secured thereto, said ring being of greater width than the width of said blades and extending rearwardly therefrom, the front edge of said ring being provided with notches between said blades, substantial] y as described.

2. In a screw propeller, the combination with blades, of a two part ring encircling said blades, said ring being concentric with the axis of rotation and having one part thereof secured to said blades, the other part thereof being adapted to remain stationary, substantially as described.

3. In a screw propeller, the combination with blades, of a two part ring encircling said blades, said ring being concentric with the axis of rotation and of greater Width than thewidth of said blades, and having one part thereof secured to said blades, the other part thereof being adapted to remain stationary, substantially as described.

4. In a screw propeller, the combination with blades, of a two part ring encircling said blades, said ring being concentric with the axis of rotation and of greater Width than the Width of said blades and having one part 50- 1o cured to said blades, the front edge of said part being notched between said blades, the other of said parts being adapted to remain stationary, substantially as described.

VENZEL PREIDEL. Witnesses:

JOHN E. BoUsFIELn, O. Gr. REDFERN. 

